Crowning die

ABSTRACT

A crowning die for use in bottle crowning apparatus defines a number of concentric throat surfaces of successively smaller diameters for forming a resealable, twist-off crown on a bottle in a single axial movement onto the bottle.

United States Patent 11 1 Sexton 1 CROWNING DIE [75] Inventor:

[73] Assignee: Peter J. Bevlaqua, Beaumont, Tex.

' a part interest James P. Sexton, Beaumont, Tex.

[22] Filed: Dec. 26,- 1972 [2]] Appl. No.: 317,953

52 us. c1. 53/341 51 Int. 01 B6 7b 3/12 [58] Field of Search.....53/341, 331, 359, 342, 343,

[56] I References Cited UNITED STATES PATENTS 1,835,990 12/1931 Lebherzu53/341 Feb. 26, 1974 6/1962 Thomas et a1. 53/331 X PrimaryExaminer-Travis Sl McGehee Attorney, Agent, or Firm--Rodney K. Caldwell5 7] ABSTRACT A crowning die for use in bottle crowning apparatusdefines a number of concentric throat surfaces of successively smallerdiameters for forming a resealable, twist-off crown on a bottle in asingle axial movement onto the bottle.

3 Claims, 6 Drawing Figures PATENTED FEB 2 61974 FIG. I

FIGS

F/as

CROWNING DIE BACKGROUND OF THE INVENTION The present invention relatesto apparatus for crowning bottles, and, more particularly, to a crowningdie for forming a resealable, twist-off crown on a bottle.

Twist-off crowns have become quite popular in many applications,replacing the older style of pull-off crown which was simply crimpedover a locking ring on the bottle neck. One feature accounting for thepopularity of the twist-off crowns is that they may be removed frombottles without the use of a conventional bottle opener apparatus. Thistwist-off feature is obtained by replacing the bottle necks conventionallocking ring with threads. Simple twist-off crowns may be formed on suchbottles from crown blanks similar to those used for pull-off crowns,using basically the same bottle crowning apparatus.

The seal achieved in applying either a pull-off or simple twist-offcrown to a bottle occurs over a substantially flat, annular area at thebottle mouth. While the twist-off crowns may be reapplied to a bottlemore tightly than the pull-off crowns, the simple twist-off crowns werenot intended to provide a resealable closure and usually cannot besufficiently tightened by hand to provide the degree of gas-tight sealnecessary to prevent carbonated beverages from going flat in a shorttime. Consequently, the simple twist-off crowns have found theirgreatest popularity in connection with single-serving sized bottles,where resealability is not a major consideration.

The demand for bottles having a resealable, twist-off crown has beengreatest with respect to large, multiserving bottles of carbonatedbeverages, particularly soft drinks and beer. Bottle and bottlingequipment manufacturers now provide bottles, crowns, and crowningapparatus for producing resealable, twist-off crowns. However, bottlersdesiring to provide their customers with products bottled in bottleshaving resealable, twist-off crowns have heretofore been required topurchase new bottle crowning apparatus at substantial cost, as theconventional crowners designed for pull-off and simple twist-off crownswere not suited to forming resealable, twist-off crowns. A large amountof bottling apparatus is presently in use in applications whererescalable, twist-off crowning is desired, but the high cost of newbottling apparatus cannot be justified.

SUMMARY OF THE INVENTION enlargements of the crown supply portions ofthecrowners and are not a part of the present invention.

The crowning dies of this invention have a number of concentric throats,or die surfaces, adjacent one another. These die throats havesuccessively smaller diameters for contacting the crown blank to form aresealable, twist-off crown as the die is moved along its axis onto theneck of a bottle adapted to receive such a crown.

It is a principal object of the present invention to provide a simplecrowning die for forming resealable, twist-off crowns, on bottlesadapted to receive the same, in a single axial movement onto suchbottles.

It is another object of the present invention to pro .vide a crowningdie for use in conventional bottle crowning apparatus for production ofresealable, twistoff crowns on bottles adaptedto receive the same.

A further object of this invention is to provide a crowning dieincluding a number of concentric throats, or die surfaces, adjacent oneanother and having successively smaller diameters for contacting andforming a crown blank into a resealable, twist-off crown on a bottle ina single axial movement of the die onto the bottle neck.

Other objects, features, and advantages of the. present invention willbe apparent from the following detailed 'description, taken inconnection with the appended claims and the attached drawing.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view of oneembodiment of a crowning die in accordance with the present invention,illustrating an arrangement of the concentric throat die surfacesthereof.

FIG. 2 is a partial bottom plan view of the embodi- I ment illustratedby FIG. 1.

FIGS. 3-5 illustrate the formation of a resealable, twist-off crown on abottle by the crowning die illustrated in FIGS. 1 and 2.

FIG. 6 is a partial cut away illustration of a bottle having aresealable, twist-off crown formed thereon by a crowning die inaccordance with the present invention, as illustrated by FIGS. 3-5.

DESCRIPTION OF PREFERRED EMBODIMENTS Resealable, twist-off crowns may beformed on bottles having a generally cylindrical seat adjacent thebottle mouth and above a threaded region on the bottle neck. The crownsare formed on the bottles and include an inner generally cylindricalseat corresponding to that of the bottle to provide a substantiallygas-tight seal. When the crown is reapplied to the bottle, these twoseating surfaces reengage and are again brought into good seatingrelationship. The presence of corresponding screw threads on the crownand the bottle neck readily enables the application of sufficiently highforces between the two seats to maintain a satisfactory seal between thecrown and the bottle.

Resealable, twist-off crown blanks differ from pulloff and simpletwist-off crown blanks in that the resealable blanks have a longerskirt, or flared, crimped edge. The longer skirt is necessitated byinclusion of the generally cylindrical seating surface between thethreads ing a body formed by rotation of a closed figure about an axis.A bottom face or die surface is indicated by reference numeral 1.Extending from the bottom surface 1 is a first generally cylindricalthroat region, or die surface, 2. Extending from this first throatsurface is a second throat surface 3 of frustoconical configuration witha diameter decreasing in the direction away from the first surface. Athird throat surface 4, also of frustoconical configuration and having adecreasing diameter in the direction away from the first surface,extends from the second throat surface 3. The slope of the third throatsurface 4 is quite small, approaching a cylinder, and is substantiallyless than the slope of the second throat surface 3.

A final throat surface 6 of the crowning die is generally cylindrical inconfiguration and has a diameter less than the smallest diameter of thethird frustoconical throat surface 4. A fourth, or penultimate, throatsurface defines a sloping shoulder between the third throat surface 4and the fifth, or final, throat surface 6. An annular top surface 7extends between the final throat surface 6 and the other periphery ofthe die 10. The throat surfaces 2-6 defined by the die 10 areconcentric. Although' each of the throat surfaces 2-6 of FlGS. l and 2is defined by the rotation of a straight line about the die axis, itwill be appreciated that the throats may be slightly curved if desired.With use, the relatively sharp junctions between adjacent throatsurfaces will tend to wear smooth.

The die surfaces 1-6 of the die member may be of any suitably hard, wearresistant material, such as stainless steel, which will provide a goodoperating life. The

exterior configuration and dimensions of the die may vary, depending onthe bottle crowning apparatus in which it is to be installed, althoughthe die will typically be on the order of two and one-fourth inches indiameter and one inch in height.

Unlike crowning dies used for forming pull-off and simple twist-offcrowns, which include a. single, smoothly sloping throat for crimpingcrowns onto bottles, the dimensional tolerances of crowning dies inaccordance with the present invention are extremely important. Thisimportance will be more readily appreciated by reference to theoperational description below, but it is apparent that if the third orthe final throat surfaces of the die are too small, bottle damage willresult during crowning. If the diameters of these surfaces are toolarge, neither good threads nor effective seating areas can be formedinthe crowns. Small variations in relative dimensions are accommodatedby a thin, commonly preformed layer of flexible material, for examplepolyethylene, provided on the inner surface of the crowns and whichserves as a gasket between the crown and the bottle, but the range ofvariation within which a satisfactory seal may be formed is small. Theabsolute values of the die throat dimensions will, of course, beunderstood to be a function of the dimensions of the bottles and of thethickness of the crowns to be formed by the die.

It will be appreciated that the number and specific configuration of thethroat regions of crowning dies in accordance with the present inventionmay vary from the embodiment illustrated herein. However, the thirdthroat surface 4 must be substantially cylindrical and have a diameteronly slightly greater than that of the bottle neck in order to form goodthreads in the crown. Similarly, the final throat surface 6 must begenerally cylindrical in order to form the seat in the crown for matingwith the generally cylindrical seatof the bottle.

The relative locations of the bottles seating surface and threadsdictate that the slope of the dies penultimate throat surface 5approximate a shoulder. It will further be appreciated that the overallheight of the die is limited by the requirement that interferencebetween the bottom of the die and the top of the bottle be avoided whenthe die is sufficiently onto the bottle to fully form the crown.

In one embodiment, a crowning die in accordance with the presentinvention was machined from a single piece of steel bar stock for usewith a CEM-3-2O bottling machine manufactured by Crown Cork and SealCompany. This die had an outer diameter of about 2-5/64 inches and anouter height of about thirteen/sixteenths inch for interchangeabilitywith the conventional, tapered-throat CEM crowning die. A firstcylindrical throat surface had an inside diameter of about 1.350 inchesand a depth of about 0.1 inches. A second frustoconical throat surface,having a greatest diameter equal to that of the first throat region,tapered from the first throat to a diameter of about 1.150 inches over aheight of about 0.3 inches, or a slope of about 0.3 inches per inchalong the edge. A third frustoconical throat surface extended from thepreceeding surface and further tapered to a diameter of 1.140 inchesover an additional height of about 0.25 inches, producing a slope ofabout 0.02 inches per inch. The penultimate throat surface tapered overa height of about 0.05 inches to the final throat, which had acylindrical configuration with an inside diameter of about 1.00 inches.

The foregoing die was installed in a CEM-3-20 hottling machine which hadbeen further modified in the area of the crown feed dial of the crownhopper, the crown chute, and the crown platform for accomplishingdelivery of the longer skirted crowns from the hopper to the properlocation for crowning. Slight modifications were also made to thepressure foot of the crowner assembly. in tests of this slightlymodified CEM-3-20 bottling machine, the above described crowning dieoperated satisfactorily under normal production conditions to formresealable,. twist-off crowns on standard half gallon bottles designedto receive such crowns.

Although the embodiment of the present invention illustrated in FIGS. 1and 2 is machined from a single piece of steel bar stock, it will beappreciated that the die may be formed of a number of segments heldtogether by an outer compressive band, by laminating a number of flat,annular elements, or by other techniques well known in the mechanicalarts.

In Operation In operation, a crown blank C suitable for forming into aresealable, twist-off crown is placed over the mouth of a bottle Badapted to receive the same as shown in FIG. 3. The crown blankinitially rests on the mouth of the bottle, and may be held in place bya pressure foot (not shown) extending through the central opening in thecrowning die. The deformable gasket material forming the inner surfaceof the crown is designated by reference character G. As the crowning dieis moved along its axis onto the neck of the bottle, the die makesinitial contact with the skirt of the crown.

With further movement of the die onto the bottle, the crown skirt ismoved toward the bottle neck, as shown in FIG. 4. As the crowning diemoves still further onto the bottle neck, the second and third throatsurfaces in turn press-the crimped skirt further against the bottle neckto form corresponding threads in the crown. Note that the outermostcrimped portion of the crown skirt is generally parallel to the axis ofthe die, and the threads formed in the crown are in its inner crimpedportion, which has been deformed outwardly by the threads of the bottle.

As the crowning die moves to the limit of its intended travel onto thebottle neck, the penultimate throat surface Sand final throat surface 6contact the crown and form a generally cylindrical seat S therein, asillustrated in FIG. 5, corresponding to the generally cylindrical seat Sat the mouth of the bottle. The die is then withdrawn along its axis,leaving the crowned bottle as illustrated in FIG. 6. The correspondinggenerally cylindrical seats in the bottle and the crown, respectively,pro vide the resealability feature in the combination.

Crowning dies in accordance with the present invention are particularlyadapted for use with existing, conventional bottle crowning apparatus,replacing the smooth throated crowning dies used in forming pull-off andsimple twist-off crowns. Accordingly, crowning dies in accordance withthe present invention enable bottlers to provide their customers withproducts in bottles having resealable, twist-off crowns without thenecessity for replacing their present bottling apparatus.

It is to be understood that the above described embodiments of thisinvention are merely illustrative of the same, and that various changesin the shape, size, and arrangement of die surfaces may be resorted towithout departing from the spirit and scope of the invention as definedby the appended claims.

What is claimed is:

l. A crowning die for forming a crown blank having a crimped skirt intoa resealable, twist-off crown on a bottle having a threaded neck and agenerally cylindrical seat on the neck above the threads and adjacentthe mouth of the bottle by a single movement of said die onto thebottle, comprising a toroidal die member defining a plurality ofconcentric throat die surfaces of successively smaller diameters in adirection away from the bottle, including:

a first throat surface having a diameter intermediate the diameters ofthe crown skirt and the bottle neck for contacting and moving the crownskirt toward the bottle neck as said die moves onto the bottle neck;

a final throat surface having a diameter slightly greater than thediameter of the seat on the bottle neck for forming a mating seat in thecrown to provide a substantially gas-tight, resealable seal with theseat on the bottle as said die moves onto the bottle neck;

at least one intermediate throat surface extending between said firstand final throat surfaces for moving the crown skirt firmly against thebottle neck to form corresponding threads in the crown; and

a penultimate throat surface approximating a shoulder between said finalthroat surface and the intermediate throat surface closest to said finalthroat surface.

2. A crowning die as recited in claim 1, including first and secondfrustoconical intermediate throat surfaces extending between said firstthroat surface and said penultimate throat surface, said firstintermediate throat surface contacting and moving the crown skirt towardthe bottle neck and said second intermediate throat surface moving thecrown skirt firmly against the bottle neck to form threads in the crownas said die moves onto the bottle neck.

3. A crowning die as recited in claim 2, wherein the slope of said firstfrustoconical intermediate throat surface is about 0.3 inches per inchand the slope of said second frustoconical intermediate throat surfaceis about 0.02 inches per inch.

1. A crowning die for forming a crown blank having a crimped skirt intoa resealable, twist-off crown on a bottle having a threaded neck and agenerally cylindrical seat on the neck above the threads and adjacentthe mouth of the bottle by a single movement of said die onto thebottle, comprising a toroidal die member defining a plurality ofconcentric throat die surfaces of successively smaller diameters in adirection away from the bottle, including: a first throat surface havinga diameter intermediate the diameters of the crown skirt and the bottleneck for contacting and moving the crown skirt toward the bottle neck assaid die moves onto the bottle neck; a final throat surface having adiameter slightly greater than the diameter of the seat on the bottleneck for forming a mating seat in the crown to provide a substantiallygas-tight, resealable seal with the seat on the bottle as said die movesonto the bottle neck; at least one intermediate throat surface extendingbetween said first and final throat surfaces for moving the crown skirtfirmly against the bottle neck to form corresponding threads in thecrown; and a penultimate throat surface approximating a shoulder betweensaid final throat surface and the intermediate throat surface closest tosaid final throat surface.
 2. A crowning die as recited in claim 1,including first and second frustoconical intermediate throat surfacesextending between said first throat surface and said penultimate throatsurface, said first intermediate throat surface contacting and movingthe crown skirt toward the bottle neck and said second intermediatethroat surface moving the crown skirt firmly against the bottle neck toform threads in the crown as said die moves onto the bottle neck.
 3. Acrowning die as recited in claim 2, wherein the slope of said firstfrustoconical intermediate throat surface is about 0.3 inches per inchand the slope of said second frustoconical intermediate throat surfaceis about 0.02 inches per inch.